According to my 3 year trading experience, the first thing you need to memorize is Dow Theory. It is the most important foundation of traders professional because thought will greatly affect the vision and trading strategy of a trader.
The Dow Theory is primarily about crowd psychology and how a real financial market works. After reading, we will have a better understanding of how the crowd works and will also feel very calm when the price of coins is sold off. In general, we will be calmer when the market is hit with waves.
The minimum amount should be 100 $ initially to trade. That number is not too big or too small, it will make you more focused and responsible with your trading strategy.